Share the Science of Giving on the white board and talk about the benefits of giving. Relate giving to gratitude - when someone gives to us, we feel gratitude, and when we give, we inspire gratitude in others. 

Give teens time to conduct research about gratitude with the intent of finding an interesting health benefit or correlation to happiness or generosity. Some ideas to get started may come from these questions: How does gratitude impact happiness? How can people develop gratitude? What is the relationship of gratitude and generosity? 

They each write a statement that describes what they learned and include the source. 

Put all the statements on a central space so they can read them all/listen to each person read theirs. Start grouping them in like categories and discuss similarities in findings. They may conduct further research to clear up confusion or contridictions. These statements may be shared creatively with other to encourage healthy expressions of gratitude for the common good and happiness of the community. 

Taking voluntary action and giving has a cost to the giver, something they give up, which may be in time, money, effort, energy, or a missed opportunity. 

The cost of volunteering is simply something you have give up in order to help another person. Opportunity cost is "the next best alternative that must be given up when a choice is made. Not all alternatives, just the next best choice." For example, when you volunteer to clean up trash by the river, you may give up the opportunity to play soccer after school. When you spend time making advocacy messages for the Humane Society, the opportunity cost may be losing time connecting with friends on social media. Helping pass out water to runners at a marathon may cost the volunteer energy.

Before taking action, the giver decides whether the benefits of giving time are greater than the opportunity cost. 

Ask, "Are you willing to give up some time or energy to contribute to someone else's happiness?"